18509428 has 24 divisors (see below), whose sum is σ = 37223424. Its totient is φ = 7888800.

The previous prime is 18509389. The next prime is 18509431. The reversal of 18509428 is 82490581.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3618 + ... + 7078.

It is an arithmetic number, because the mean of its divisors is an integer number (1550976).

Almost surely, 2^18509428 is an apocalyptic number.

It is an amenable number.

18509428 is an abundant number, since it is smaller than the sum of its proper divisors (18713996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18509428 is a wasteful number, since it uses less digits than its factorization.

18509428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3663 (or 3661 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 18509428 is about 4302.2584766608. The cubic root of 18509428 is about 264.5235440131.

The spelling of 18509428 in words is "eighteen million, five hundred nine thousand, four hundred twenty-eight".